<html>
    <head>
        <title>Unit</title>
        <style>
            html {
                font-size: 16px;
            }
            .ems li {
                font-size: 2em;
            }
            .rems li {
                font-size: 2rem;
            }

            .wrapper {
                width: 600px;
                border: 1px solid;
                display: flex;
            }
            img {
                border: 3px solid purple;
            }
            .box {
                width: 200px;
                margin: 20px;
            }
            .img-width {
                width: 100%;
            }
            .img-max-width {
                max-width: 100%;
            }
            .minibox {
                width: 50px;
                margin: 20px;
            }
        </style>
    </head>
    <body>
        <div class="ems">
            <ul>
                <li>em One</li>
                <li>Two</li>
                <li>
                    three
                    <ul>
                        <li>Three A</li>
                        <li>Three B
                            <ul>
                                <li>Three B one</li>
                            </ul>
                        </li>
                    </ul>
                </li>
            </ul>
        </div>
        <div class="rems">
            <ul>
                <li>rem One</li>
                <li>Two</li>
                <li>
                    three
                    <ul>
                        <li>Three A</li>
                        <li>Three B
                            <ul>
                                <li>Three B one</li>
                            </ul>
                        </li>
                    </ul>
                </li>
            </ul>
        </div>

        <div class="wrapper">
            <div class="box"><img src="background/star2.png" class="img-width" /></div>
            <div class="box"><img src="background/star2.png" class="img-max-width" /></div>
            <div class="minibox"><img src="background/star2.png" class="img-width" /></div>
        </div>
    </body>
</html>